You can add bank accounts to QuickBooks Online (QBO) via the mobile app and on the web, vikas. I'll guide you through the process below.
Using the mobile app, you have the option to connect a bank account through the Menu icon. For the step-by-step guide, here's how:
Go to Menu☰, then select Transactions.
Select + to add an account.
Search for your bank. Or choose from the list of popular banks.
Select your bank from the search results.
Sign in to your bank.
Follow the steps to select an account to connect to.
Select a QuickBooks account the bank account should map to.
If you're not seeing the menus mentioned above, I'd recommend uninstalling (tap and hold the app icon) and reinstalling the app. This ensures the version you'll be using is updated.